Ignition apparatus



Sept- 15, 1936- K. A. HARMON ET AL IGNITION APPARATUS Original Filed June 15,

1935 3 Sheets-Sheet l v ATTO NEYS.

p 1936- K. A. 'HARMON ET AL 4,4

IGNITION APPARATUS Original Filed June 15, 1935 3 Sheets-Sheet 2 p 6- K. A. HARMON ET AL 2,054,462

IGNITION APPARATUS Original Filed June 15, 1935 3 Sheets-Sheet 5 l I II INVENTOR. lily/ram Ale/WM Mo BY Ema-1c: 6. Laws ATTORNEYS.

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Patented Sept. 1 5, 1936 IGNITION APPARATUS Kenneth A. Harmon and Terrence G. Louis, West Springfield, Mass., assignors to Wico Electric Company, West Springfield, Mass., a corporation of Massachusetts Original application June 15 1935, Serial No.

Divided and this'application October 11, 1935, Serial N0. 44,566

5 Claims. (Cl. 123-148) This invention relates to an improved ignition apparatus for internal combustion engines.

This application is a division of our application filed June 15, 1935 under Serial No. 26,726.

The invention is capable of general application, It is suitable for use in automobiles, trucks, tractors, motor boats, airplanes and stationary power plants, and so forth. A typical use is in connection with an automobile and such use will sufiice as an illustrative example to show the advantages and utility of the invention.

The now prevalent type of ignition apparatus used in automobiles consists of aninduction coil, deriving its current from the storage battery, which also supplies current to the starting motor used to crank the engine. This so-called battery ignition system has several disadvantages.-

An inherent weakness in such a system is that spark current diminishes as the engine speed increases and, on the higher speeds, decreases to such an extent that the-eflectivenessof the spark is seriously impaired. Such action occursbecause magnetic flux can be built up in the core of the induction coil only during .the intervals when the breaker points are closed, and the time length of these intervals diminishes as the engine speed increases. And these intervals at the very high speeds are not sufficiently long to enable the magnetism to build up in the core of the induction coil to the same degree that it can in the longer intervals available on slower engine Another disadvantage of such system is that it is diflicult, in extreme cold weather, to secure an effective ignition spark. ,The difficulty here is that the heavy load imposed on the start ing.motor in turning over the cold engine, results in a heavy current being drawn from the battery, whereby there is a severe drop in battery voltage. If, for example, the battery voltage drops down to 2 or 3 volts, the current in the primary of the ignition coil will be seriously reduced below the normal value obtained under a normal voltage of say 6 volts. A further disadvantage of the battery ignition system is the This current consumption is not, of course, a constant load and occurs only during the times when the breaker points are closed. However, i in battery-ignition systems the effort is to keep they open,such.action increasing as the current flow increases.

The other type of ignition system, formerly used on automobiles but now generally abandone'd, is the magneto type. The weakness of this system is the absence of an effective spark on starting. But the magneto has a very important characteristic, which makes it most desirable for the modern automobiles operating at very much higher speeds than heretofore. This characteristic is that the effectiveness of the spark increases as the engine speed increases. This same characteristic accounts for the disadvantage of the magneto for ignition on starting but, if this disadvantage can be overcome, then the magneto offers the best solution for securing efiective ignition on the very high engine. speeds now being used.

The apparatus of this invention combines both of the aforesaid types of ignition, operating on the battery-energized induction coil principle on starting and on the magneto principle for normal running. Attempts have been made heretofore to combine in an ignition apparatus both the stated types of ignition but, in no case, so far as we are aware, has the problem been solved com pletely and effectively, so as to be followedup by a commercial development such as to render available a commercially satisfactory ignition apparatus combining the advantages of both the aforesaid systems, notwithstanding the neecl which has existed and is existing for an apparatus of this sort.

This invention has for'its general objects to provide an ignition apparatus which will produce than the conventional battery ignition system and which will produce an effective spark even under unfavorable cohditions, such as that of .a partially run down battery'or that where there is a heavy drop in the battery voltage due to a heavy withdrawal of current by the starting motor in cranking the engine in cold weather; which will produce a much better spark than the conventional battery-ignition system on extremely high engine speeds; in which a reduction in the wear on the breaker points may be effected because of the substantial reduction in current flow during medium speeds of engine operation; and in which the aforesaid results of better ignition I are effectedby a more eflicient utilization of the battery current with a substantial saving in current over theconventional battery-ignition system and thus a lessened drain on the battery.

The invention also has for an object the provision of an ignition system, operating on the battery-energized induction coil principle for starting and at other times on the magneto principle, wherein the same primary and secondary coils are utilized for operation onthe induction coil principle as well as on the magneto princi- 1 ple,-the arrangement being characterized in that the primary coil has a much less resistancethan the usual primary of an induction coil and is purposely designed to produce good sparking at low engine speeds on the magneto principle of operation,such primary coil because of its low resistance also enabling an adequate flow of current through it from a partially depleted battery, or one subjected to a heavy-voltage drop, to produce good sparking when operating on the induction coil principle.

More particularly, the invention has for an ob- 4 ject the provision of an ignition apparatus including a magnetizable core with primary and secondary coils thereon, breaker points controlling the Drimary coiland operating in timed relation with the engine, an energizing coil deriving current from the battery and creating magnetic flux which is distributed to and from thecore by engine-driven flux distributers, and a switching means in the magneto operable by remote control for directing battery current through the primary coil and the breaker points, during the starting period, and for disconnecting the battery from the primary coil at all other times to allow the spark to be produced on the magneto principle by the changes in flow of 'magnetic flux effected in said core by the action of said flux distributers magnetized by said energizing coil.

' Another and important object is to arrange the aforesaid switching means so as to effect disconnection of the energizing coil from the battery during operation of the apparatus on the induction coil principle, 'whereby the magnetization of the core by the flow of battery current through the primary coil, is unopposed by flux produced Y by the energizing coil.

The invention has for another object the provision of a-single and stationary energizing coil with laminated rotors or flux distributers, one on each side thereof and fixed to an engine driven shaft, and cooperating to direct flux to and from the core carrying the primary and secondary coils. This arrangement contributes to the production of a compact, light weight unit, with-the weight of rotatingparts reduced to a minimum, and avoids not only the extra cost of' slip rings necessary to conduct the battery current to a rotating ,coil but the troubles experienced in 0ption;

eration'due to faulty contacts at such slip rings. These and other objects will moreparticularly appear as the detailed description proceeds and will be pointed out in the appended claims.

The invention will be disclosed with reference to the accompanying drawings, in which:

Fig. 1 is a-centralsectional elevational view of an ignition apparatus embodying the inven- Fig. 2 is an end elevational view of the breaker point mechanism;

Fig. 3 is a cross sectional view taken on the line 3-3 of Fig. 1;

Fig. 4 is a fragmentary top plan view,- showing the ignition coils,the cover therefor having been removed;

Fig. 5 is a view, taken similarly to Fig. 4 except that the ignition coils and their core have been removed to reveal the pole piecw;

Fig. 6 is a cross sectional view taken on the line 6--6 of Fig.4;

Fig. 7 is an end elevational view of the switch unit shown in Fig. 6; I V

Fig. 8 is a fragmentary cross sectional vie taken on the line 8-8 of Fig. 4; and I Fig. 9 is a diagrammatical view showing the various electrical unitsof the apparatus, with their connections and the complete ignition system formed thereby.

Referring to Fig. 1 of these drawings, the .ap-, paratus is contained in a casing I, having a cylindrical bore 2 closed at one end by a head 3, in

which a suitable.anti-friction bearing 4 is mountadapted to be magnetized by the coil when the latter is energized. Coil ll is statlonarily supported in the bore 2 intermediate the ends thereof. Shaft 8 has fixed to it in axially spaced relation two flux distributers I0 and II, disposed one on each side of the energizing coil 9 of the electromagnet. As shown in Fig. 3. these flux dis-- 'tribute'rs are of like construction but one is angularly spaced from the other. Each is made up of soft iron laminations (Fig. 1 held together as by rivets II, and each includes a'plurality (three in the form shown in Pig. 3) of arms radially projecting from the shaft. These radial arms, in the form disclosed, are equally spaced around shaft I. The members I. and II are keyed to the shaft (Fig.1) and eachis also clamped in axial position against a shoulder I! by a nut l3, threaded on the shaft. In the form herein shown, each radial arm of the distributer In is angularly spaced from the corresponding arm of distributer II by an angle of degrees.

These flux distributers are adapted'to direct flux from the electromagnet to. and from a core ll, made up of soft iron laminationasuitablyheld together as by rivets l4. Onthis core are mounted primary and secondary coils l5 and I6, respectively. The distributersnot only make and break a magnetic-circuit through this core a plurality of times during each revolution of shaft-:18 but, preferably also, effect this result by creating reversals of flux through the core, as will later appear. For these 1 1 8 the flux distributers cooperatewith pole pieces made up of Figs. 1 and 3.

soft iron laminations and suitably fixed in the casing I and in this instance embedded therein during the process of casting the casing. There are two pairs of these pole pieces (Fig. -5), one

pair for each distributer, the members of one pair being mark'ed I "I and I8 and the corresponding members of the other pair being marked I1 and [8, respectively. The pole pieces I1 and. I3 lie in the same transverse'plane as the distributer l0 (Fig. 1) and the pole'pieces I1 and I8 lie in the same transverse plane asthe distributer I0. approximately tangential to the cylindrical portionihereof and through this face is an opening leading into bore 2 ,(Figs. 3 and 5)., Each pole piece has one end formed with a fiat face 20 lying in the plane of said flat face IS. The other end of each is formed with an arcuate surface 2| concentric with the shaft 8 and adapted to cooperate with the arcuate ends of its flux dis-f I8 are similarly connected by a similar bridgev 24. The ends of each bridge rest directly on the flat faces 20 of the.pole pieces. The core I4 interconnects the bridges22 and 24 (Figs. 3 and 4). and its ends rest directly on top of the bridges in seats provided for this purpose as shown in Clamps 25, one at each end of core I4, are secured to casing I by screws 26 and act to press the core ends tightly against the bridges and the latter tightly 2|! of the pole pieces.

The arms of each flux distributer and the pair of pole shoes, with which it cooperates, are so spaced that when one arm is covered to, any substantial extent by one pole piece of a pair, the other arms are entirely out of covering relation with the other pole piece of the pair. And the two distributers are angularly spaced so that when one arm of one, as I0, is coveredfby a pole piece, as l8, one arm of the other, as Ill, is covered by the opposite pole piece, as ll. Thus, with the distributers positioned as described, flux will then flow from the distributer of north polarity, say I0, through pole-piece I8 and bridge 24ltothe right hand end (as viewed in Fig. 3) of core I4 and return from the opposite end of the core through-bridge 22 and pole piece H to distributer ill. from pole piece H to distributer I0 .nor from pole piece. I 8" to distributer l0. On continued rotation of shaft '8, that arm of distributer Ill which was covered by pole piece I8 moves out of covered relation therewith anda succeeding arm becomes covered by pole piece I1 and the arm then pass from pole piece I'I' to distributer l0 nor from pole piece I8 to distributer I0. Thus,

each arm. of each -'distributer cooperates succes- .sively with its pair of pole pieces to establish magnetic flux in core II first in one direction and then in the opposite direction. Three times during each revolution of shaft. 8, magnetic flux is established in one direction through core I! and three times during each revolution flux is established in the opposite direction in core M.

The casing I has a fiat face I9,

against the faces Flux cannot at this time pass' Theresult is that flux is built up in the core six times during each revolution but alternately in opposite directions so that the transition is from a maximum in one direction to a maximum in the other directiomfwhereby a large efiective flux change can be utilized in the core toinduce a current in the coils thereon. The reversal of flux in core I4, while important and preferred, is not essential to the broader features of the invention. I

The arrangement described is suitable for a six cylinder engine in which the cam shaft, travelling at one-half the crankshaft speed, drives the shaft 8. It is contemplated that the arrangement may be varied to suit engines having a greater or less number of cylinders by varying the number of arms on the flux distributer and the angular extent of the arcuate surfaces of the several pole pieces;

The casing I is, of course, made of non-magnetic metal, such as aluminum for example. Cooperating with.the casing I to enclose the core I4 and coils l5 and l6,-is a cap 21 of insulating material such as bakelite. This cap rests on the surface I9 of easing l and is secured thereto by screws 28. The cap 21 has mounted therein 7 face of the rotatable race of ball bearing 4 by a screw 32, threaded into shaft 8, the head of the screw being received in thecounter-bored end of the cam as shown. The stationary breaker point 33 is carried by a metallic bracket 34 fixed to head 3 and thereby grounded. The movable breaker point 35 is fixed to one end of an arm 36 of insulating material. This arm' is pivoted intermediate its ends on a stud 31 fixed to head 3 and the other end of the arm serves as a follower to be engaged and moved by cam 3|. A fiat Spring 38 is secured at one end to arm 36 in electrical contact ,with point 35 and at the other end by a for the purpose of adjusting the breaker point 33 relatively to its companion breaker point 35. An eccentric stud II, mounted to turn in head 3, engages in a slot in bracket 34, and when this stud is turned the bracket will be swung on its pivot.

. The cam 3|, as shown, is of hexagonal cross sectional shape and its six projections successively engage and move the arm" 36 and cause the tributer cap 43 (Fig. 1) of insulating material. Spring clips 44 (Fig. 2), each pivoted to and between a pair of lugs on flange 42, engage in recesses in cap 43 (Fig. 4) in the usual way and hold 58 mounted on the distributer brush arm 5 I the cap to its seat on flange 42 against axial and turning movement. The cap (Fig. 1) has a circular series, six in this case, of contacts 45 each connected to an exterior binding screw 46. To the screws 46 are connected the high tension wires 41 leading to the spark plugs s of the engine (see Fig. 9). The case also carries a central terminal 48 :to which the lead wire 38 from the secondary coil I6 is connected. This terminal on its innerend carries a spring pressed plunger 48 which engages the inner end of a conducting strip The brush arm, which is of insulating material, telescopes over the outer end of the breaker point cam 3I and has a projection 52 fitting in a recess in the cam to effect an operable driving engagement. ,The outer end of strip 58 is movable successively into close proximity to the contacts 45 and thus the high tension current is distributed in proper order to the several spark plugs s.

Variations in the timing of the spark may be effected in any desired way. All that is necessary is to turn the breaker point mechanism relatively to its operating cam 3| and this may be done either by turning the casing I relatively to shaft 8 or by turning shaft 8 relatively to the casing. A timing adjustment of the breaker point mechanism results in a corresponding adjustment of the distributer because. the distributer brush is fixed to the cam 3| and the distributer cap is fixed to the head 3 which carries the breaker points.

In Fig. l, we have shown a cup-shaped casing 53, secured in abutting relation-with the head 5, to casing I by the described screws 6. The casing 53 houses a centrifugal governor of well known form for advancing the shaft 8 relatively to the shaft whichdrives it,in this-case a shaft 54 mounted in a hub-like extension 55 of casing 53. Fixed to the inner end of shaft 54 is a member 56 to which are pivoted at diametrically opto describe this device in detail as it is not in otherwise, to secure variations in the timing of the spark. Either or both forms of spark advance means may be used as desired- Within the described socket is located one end of an engine driven shaft and the shaft 54 is shap d. as indicated, for a coupling engagement with such engine driven shaft, when hub 55 is inserted in said socket.

Referring to Fig. 6.111s casing I, at a point near the head 3, is built out at diametrically opposite locations'into generally rectangular form,

to provide two'opposed chambers 62. and 63 of rectangular cross sectional shape, leading outwardly from bore 2. In the chamber 62 is mountlel with but slightly below the surface I8. This strip has three binding posts 18, 'II and I2 thereon. The terminals of the primary coil I5 are connected by wires I3 and I4 (Fig. 4) to the posts II and 12, respectively. A wire (Fig. 6) connects the insulated terminal 66 of the condenser to post 12 and a wire I6, extending through head 3, conn ects the terminal 38', and thus the insulated breaker point 35, to post 12. p

The magnet coil 8 (Figs. 1 and 3) is mounted within a short cylindrical casing TI of insulating material,- including a cover 18. This casing has diametrically disposed lugs 18 (Figs. 1 and 3), projecting radially outward and engaged in paralleling the axis thereof. The casing 11 may thus'slide in an axial direction in thecasing I and the grooves 88 extend from the open end of bore 2 to a, point about midway thereof. In the assembling operation, shaft 8 with the casing 11 loosely mounted thereon between the rotors, is

82 (Fig. 3) which extend throughcasing I at digrooves 80 formed in the bore 2 of easing I and ametrically opposite points and threadinto metallic inserts 83 (see also Fig. 8) molded in the casing. The terminals of'the magnet coil 8 are connected one to each insert 83. The screws 8I and 82, which are insulated from casing I by washers 84', thus hold the casing "IT in place and also serve as terminals for the magnet coil.

The chamber 63 (Fig. 6) serves to house a control switch which is mounted on the inner face of a plate 86, secured by screws 81 to the casing to close the outer end of the chamber. This switch is operated under remote control by an electromagnet, including a magnetic core 88, a magnet coil 88 thereon and an armature 80, pivoted to plate 86. This electromagnet is secured to a bracket 85 fixed to plate 86 by bolts 85. One terminal of coil 88 is grounded to bracket 85 and the other is connected by a wire 88" to a terminal bolt 8| which passes through and is insulatedfrom bracket 85 and plate 86. The armature actuates through the intermediary of slidable push rods 82 of insulating material, two spring fingers 83 and 84 (Fig. 7) which are fixed to bracket 85 by the bolts 85 and which are insulated from the bracket as indicated. The finger 83 is normally engaged with a. stationary and grounded contact 85 and becomes disengaged therefrom when the magnet coil 88 is energized. The finger 84 likewise normally engages a stationary and grounded con-.. tact 86 but, when it is moved on energization of' the magnet coil 88 it not only becomes disengaged from contact 86but also engaged with a contact 81, carried by a finger 81, fixed to bracket by a wire as to the described binding post H and thus to one terminal the primary coil I5. The

finger 93 is connected by a wire 99 to the binding post 10 and a wire I00 leads from this post to a terminal IOI, mounted onand insulted from a plate I02 which is secured by Screws I03 to casing I and closes the outer end of chamber 62. The

terminal IIlI is connected by an insulated conductor I04 (Fig. 4) outside the casing I, to theterminal 82 of the magnet coil I.

The work accomplished by the switch unit just described, as well as the operation of the apparatus, will best be understood from the diagram in Fig. 9 which shows all the electrical elements above described and their connections with other battery, usually of six volts. One side of the bat-,

tery is grounded and the other side is connected by a wire I06 to one terminal of switch S. The other terminal of switch S is connected by a wire I0! to one side of motor M and the other side of motor M is grounded. The usual ignition switch is shown at I and one terminal of it is connected by a wire I08 to the ungrounded'side of battery B and the other terminal thereof is connected by a wire I09 to the terminal 8| of magnet 9. A wire H0 leads from wire I01 to the terminal 9| and thus to the magnet coil 89, whereby this coil will be energized from battery B when. and only when the starter switch is closed. The other electrical connections have already been described.

In operation, the operator proceeds in the same manner as is usual with battery ignition systems. That is, he closes the ignition switch I and then presses on thestarter switch S to close it and hold it closed until the engine has been started by motor M. The closing of the ignition switch in this case serves only to close a circuit through the magnet coil 9. This circuit'is as followsirom battery B by wires I06 and I98 to and through switch I, thence by wire E09 to terminal ill of coil 9, thence from coil terminal ,82 by way of wire I04 to terminal II and by way of wire I90 to terminal, thence bywire 99 to switch finger 93 and contact 95, and by the ground back to the battery; The closing 01. the starter switch S serves, in addition to its usual-and normal purpose, to establish the starting ignition circuit. It causes the energization of the magnet coil 89 and insures the deenergization of magnet 9. Current flows from wires Hi6, I01 and I I0 to terminal 9| and thence by wire 89 to coil 89 and'from the coil by way of the ground connection back to the battery. On energization of coil 99, the airmature 90 is pulled in by the then magnetized core 88 and the fingers 93 and 94 are moved from their normal positions illustrated. Movement of finger 93 simply opens up the circuit to magnet 9. Movement of finger 94 first breaks the ground connection 96 of the primary coil I and then closes a circuit from the battery. B through the primary ger 94 by the magnet 09 breaks the last named ground connection of the primary circuit and extends such circuit as followss-through contact 91, finger 91' to terminal 9|, thence by wires H0 and IN to switch S; and thence by wire I06 to the battery B and to the ground. This is the "start ingcircuit and exists only for the short intervals during which switch S is held depressed. At such times, current from battery B will flow through the primary coil I5 whenever the breaker points 33 and 35 are engaged. The coils I5 and I6 then function on the same principle as the usual battery ignition coil. And during this interval, the electromagnet 9 is deenergized so that no magnetic flux from that source will be present in core I4, to interfere with the magnetization of the core by battery current flowing through the primary coil I5. However, the instant that switch S is released, magnet 89 is deenergized and tact 96 to reestablish the normal primary circuit.-

lishes the circuit from the battery through coil 9.-

The apparatus then functions as a magneto,the distributers I9 and I0 creating flux changes in core I4 and causing the generation of current in the windings I5 and I6. The same breaker points control both the starting and running circuits of the apparatus. 4

In the operation of the apparatus as a magneto, flux from the electromagnetic source 9 is allowed to build up in core 64 under conditions as favorable as possible. That is, the primary circuit is kept open for relatively long intervals to allow the flux to build up in the core without the opposing influence of a short circuitedprimary coil.

' The breaker points, in the form of apparatus herein disclosed, complete one cycle of operation in g E S.

are closed about two-thirds of the time and open only about one-third of the time. In Fig. 3, the flux distributers are shown in the positions which they occupy at the moment the breaker points open. Flux will then build up in core I4, flowing from right to left, the circuit being from the nearly vertical distributor arm I0 through pole piece 88, bridge 24, core It; bridge 22, pole piece II to that distributor arm I0 which in Fig. 3 lies immediately to the left of the aforesaid arm I0. The breaker points remain open until these two arms I0 and I0 become completely covered by their respective pole pieces I8 and I1 and until these arms start to leave such pole'pieces. Then the breaker points close and the then short circuited primary coil tends to resist a change of flux in core I4. This condition continues until the aforesaid two arms l0 and I0 have moved far enough away from the forward edges of their respective pole pieces to create substantial gaps, such 'as those shown at g and g in the magnetic circuit. Then the breaker points again open and a sudden change of flux occurs in core I4. But this change is not simply from a maximum to zero but from a maximum in one direction to zero and beyond to approach as near as possible to a maximum in the other direction. For at the time of 1 the opening of the breaker points, the aforesaid arm I0 has moved into partially covered relation with pole piece I8 while asucceeding arm I 0 has moved into partially covered relation with the pole piece I'I; Flux then flows from left to right in core I4 and thus in the opposite direction to the flow of flux previously established. Hence, in the magnetic change, a reversal of flux is secured. Such a flux change in core I4 is effected six times during each revolution of shaft 8 to produce an ignition spark in the usual manner. This gives the-three sparks per revolution required for'the six cylinder engine. It should be particularly noted that the primary'coil I is not the same as the primary coil used in the conventional battery ignition system, although it operates on the same principle during the interval when battery current is directed through it. The coil is primarily a magneto coil and has fewer turns of larger wire and much less resistance than the average primary of an in- 'duction coil. The coil I5 is purposely designed to produce good sparking at low engine speeds on the magneto principle of operation. .While the usual primary of an induction coil could be used as the primary of the magneto, its resistance, which is usually about four times as great as that of coil l5, would be too great to allow good sparking to be produced when the engine is operating at low speeds, especially where as here, the flux distributors are rotating slower than the engine at half the speed of its crankshaft. Thus, the primary coil I5 is essentially a magneto primary and does not havethe same characteristics as the primary of an induction coil. And due to this fact, an important advantage is secured. Because of the low resistance of coil i5 an adequate flow of current through it can be secured even with a partially depleted battery or with a nondepleted battery which is subjected to a. heavy voltage drop due to an unusual starting load. As an illustrative example and without setting up limitations, the coil l5 may have 'a resistancesuch that it will draw six amperes at three volts or half the usual battery voltage. This is as great a current as the average primary of an induction coil would draw from the battery at six volts. Thus, the coil I5 is enabled to produce better ignition, under the unfavorable battery conditions named, than the conventional battery ignition system and under normal conditions it produces a better spark due to the heavier current flow say 12 amperes. In this way, the problem of a good spark at starting, even under unfavorable conditions,

has been solved and .a better starting spark under all battery conditions is eflfected than in the conventional battery ignition system.

The use of such a heavy-current flow would be fatal if the flow were continued for any great length of time. The heavy arcs produced at the breaker points and the consequent burning of them would soon destroy them. Therefore, it is imperative that the time during which such heavy currents flow across the breaker points. be reduced to the barest minimum. It cannot safely be leftto the judgment of the operator when to change from battery ignition to magneto ignition. At best, he would needlessly prolong the interval during which the apparatus operates on the in- '-duction coil principle and a careless operator might forget to make the change withthe result that the breaker points would soon be destroyed.

Then the system would be condemned as unsuit-- able. Therefore, the provision of the automatic means for predetermining and limiting the times of operation on the induction cofl principle is a most im t t factor and, it is believed, the

key to success in the production of a commercial- 17 successful ignition apparatus of the type in whichthe induction coilprinciple and magneto principle are combined. Such automatic means,

operator and no change other thanrunning a wire, such as ill], from the starter switch to the terminal 9| of the ignition apparatus.

In fact, the apparatus requires no substantial change for its installation. If originally installed in the automobile, one puts the ignition unit in the place usually occupied by the timer and distributer unit. After that, the wire from the ignition switch I is led to the terminal 8| of the energizing coil 9 instead of to the usual ignition coil. The only additional wiring is the wire 0, above described.

The use of the ignition apparatus of this invention results in a smaller consumption of current in a given time than the conventional battery ignition system. A heavier current is used on starting but this heavy flow is only momentary, usually a matter of a few seconds. In nor mal running, current from the battery is used medium engine speeds, dwindling to lesser values at the higher engine speeds with resulting loss in effectiveness of ignition. Of course, the current used for the energizing coil is a constant load during operation of the engine, whereas in the conventional battery ignition system, the current flows only while the breaker points are closed.

. But it is essential in-a battery ignition system that the breaker points be closed as longas possible in order to get as much time as possible for the building up of flux and usually they are closed about 70%- of the time. Therefore, there is a substantial saving in battery current through the use of this apparatus. 7 w

The invention effects a reduction in the wear on the breaker points over that resulting from the use of the conventional battery ignition system. In order for the induction coil of the last named system to' produce a reasonably good low speed spark and a reasonably good high speed spark, it is necessary to pass a much higher current through it at medium speeds than would otherwise be necessary and than is used in the present apparatus. Consequently, the larger amount of current flowing across the breaker points during the intervals of medium engine speed operation, and these are usually the longer intervals of engine operation, results in more tion well on highspeeds will not flmction well on low speeds and vice versa. 7 The difference in current flow under thae two conditions is too great to allow one condenser to properly work under both conditions. But in magneto mention there is not such a wide differential and it is a fact that one condenser will f mction much more effectively throughoutthe speed range than in a battery ignition system, and this fact means lessened wear and longer life of the points. While the condenser does not function as well during periods of battery operation, these periods as above set forth, are purposely made exceedingly short so that the war occurring from this cause is so reduced as to be negligible.

The apparatus of this invention produces a better s'park at high engine speeds. The more rapid the engine speed, the more rapid is the flux change produced by rotation of the distributers l and I0 and the rate of change of flux as well as the amount of change is a factor in the production of the spark: Then, the flux is built up in the core l4 under the most favorable conditions, viz., while the breaker ,points are open and thus without the opposing choking influence of a short-circuited primary. With the conventional battery ignition system, time is an important factor in the establishment of flux in the core of the induction coil. Magnetization occurs only when the breaker points are closed and.

builds up relatively slowly. Naturally, as the en-.

gine speed increases, less and less time .is available for the building up of flux, wherefore the current falls off and poor sparking results. In contradistinction to the practice employed in conventional battery ignition systems ofkeeping the breaker points closed as long as possible, the practice here is to keep them open as long as possible and close them only for short intervals to hold the flux while a gap is created in the magnetic circuit preliminary to the ensuing break.

The apparatus is a compact, light weight unit, complete in itself and requiring only two wire connections to the battery, as above described. It utilizes an energizing coil in place-of the'more expensive magnets of. cobalt steel which would be necessary to use to secure a degree of compactness approaching that herein disclosed. But

the use of the coil is important for the reason that the action of the magnetic source can be discontinued during periods of induction coil operation so as not to interfere therewith, whereas the harmful action of permanent magnets at such periods cannot be so easily avoided. It is deemed important that the coil 9 be stationary. Use of slip rings is avoided as well as their initial cost and the troubles in operation likely to arise from their use. The weight of the rotating parts is also reduced by not mounting the coil 9 on thesha'ft 8 and it is important to keep the weight of rotating parts as low as possible and reduce the wear on the moving parts. The pole piece arrangement, with the bridge pieces and the core which interconnects them, is important in that it enables the use of flux distributers of simple and inexpensive form and of a form which can be made up of laminated soft iron stampings as is desired for their excellent magnetic qualities. Specially shaped and expensive forgings, which are also less desirable because of their poorer magnetic quaities, are avoided.

The invention thus provides an improved ignition apparatus, characterized in that it is adapted to more efliciently utilize the battery current and secure better ignition with a less. consumption of current than in a conventional battery ignition system and characterized also in that it is capable of producing a better starting spark and a better spark at high speeds and a good starting spark under unfavorable battery cond tions where the said conventional system wou i system.

The features disclosed herein and relating to.,, dual ignition, wherein the transition from one form to the other is automatically efiected in coordination with the operation of the starter motor, are claimed in our above-named applica-.

tion filed June 15, 1935 under Serial No. 26,726.

The features disclosed herein relating to magneto construction, apart from duel ignition, form the subject-matter of and are claimed in our application filed October 11, 1935 under Serial No. 44,567.

What we claim is:

1. Ignition apparatus for an. internal combus- I tion engine, comprising, a soft iron core, primary and secondary coils on said core, an interrupter, a c1rcu1t including said primary coil and interrupter and adapted to be opened and closed by the opening and closing of the interrupter, a batmeans for connecting said circuits together to cause battery current to bedirected through the primary coil during its closed'circuit intervals and ignition sparks produced on the induction coil principle, said primary coil having a sufliciently low resistance to enable efiective sparks to be produced by the action of said flux distributing members at low engine speeds and also to enable effective sparks to be produced on the induction coil principle when battery current at substantially less voltage than normal is directed through the primary coil.

2. Ignition apparatus for an internal combustion engine, comprising, a soft iron core, primary and secondary coils on said core, an interrupter, a circuit including said primary coil and inter-- rupter and adapted to be opened and closed by the opening and closing of the interrupter, a battery, an electromagnet including a magnet core and a coil effective when energized to magnetize the magnet core, a circuit including said battery and electromagnet coil, flux distributing members connected to the magnet core and driven by the engine, said interrupter being driven by the engine to periodically open and close the primary circuit, said members cooperating with the first named core to establish flux through said primary coil during its open circuit intervals, and switch means for connecting said circuits together to cause battery current to be directed through the primary coil during its closed circuit intervals and ignition sparks produced on the induction coil principle, said primary coil having a sumciently low resistanceto enable effective sparks to be produced by the action of said flux distributing members at low enginespeeds and also to enable effective sparks to be produced on the induction coil principle when battery current at.

through the primary coil, and switch means op.- erable simultaneously with the. above-named switch means for interrupting, the circuit of the coil of said electromagnet, thereby discontinuing the magnetizing action of the flux distributers on the first-named core during the period when said core is being periodically magnetized by the flow of battery current through said primary coil,

3. In combination, primary. and secondary coils, a core therefor, a source of magnetic flux including an energizing coil, means for periodically directing magnetic flux from said source through said core, circuit breaking means periodically operable in timed relation with the firstnamed means, a normal circuit including said primary coil and circuit breaking means, a casing for all the aforesaid elements, a battery outside the casing, a circuit including'said battery and energizing coil, a starting circuit including said battery in addition to the normal circuit, a switch within said casing for changing the normal circuit to the starting circuit and vice versa and normally positioned to establish the normal circuit,

'remote' control means for moving said switch from its normal position to a position wherein said starting circuit is established, and means operable bysaid remote control means for interrupting the circuit of said energizing coil.

4. An ignition apparatus for internal combustion engines, comprising, a stationary soft iron core, primary and secondary coils on said core, a rotary and magnetizable shaft adapted to be driven. from-the engine,- a stationary coil encompassing said shaft and effective when energized to magnetize the same, a battery. in circuit with the magnetizing coil for energizing the same, soft iron flux distributers fixed to said shaft one on each side of the magnetizing coil and 'cooperating with saidcoreto alternately make and break a magnetic circuit therethrough, cooperating and relatively movable breaker points, a normal.circuit including said breaker points and primary winding andadapted to be opened and closed by the opening and closing of the breaker points, means driven from said shaft for operating said breaker points to open them when the magnetic circuit through the core is broken by the action of said distributers and hold them open while the distributers establish flux in said core and then close them, and means including a switch for changing said normal primary circuit to include said battery whereby current therefrom may pass through the primary coil when the breaker points are closed to induce a current in said'secondary coil.

5. An ignition apparatus for internal combustion engines, comprising, a stationary soft iron core, primary and secondary coils on said core, a

' rotary and magnetizable shaft adapted to be driven'from the engine, a stationary coil encompassing said shaft and effective when energized to magnetize the same, a battery in circuit with the magnetizing coil for energizing the same, soft iron flux distributers'flxed to said shaft one on each side of the magnetizing coil and cooperating with said core to alternately make and break and changing said normal primary circuit to in-' clude said battery whereby current therefrom may pass through the primary coil when the breaker points are closed to induce a current in said secondary coil.

KENNETH A. HARMON. 'I'ERRENCE G. LOUIS. 

